Broadband Circularly Polarized Light Detection via Spin‐Selective Charge Transport in Quantum Dot Photodiodes

ABSTRACT Circularly polarized light (CPL) detection provides polarization‐resolved information, enabling advanced applications in quantum technologies, bioimaging, secure communications, and multi‐level optical data processing. However, conventional CPL photodetectors typically rely on intrinsically chiral absorbers, restricting operation to the UV–vis range and hindering extension into the near‐infrared (NIR) and shortwave infrared (SWIR), which are critical for deep tissue imaging and low‐visibility sensing. Here, we demonstrate broadband CPL detection with quantum dot (QD) photodiodes that exploit the chiral‐induced spin selectivity effect in chiral‐ZnO charge transport layers. Chiral ligand‐functionalized ZnO electron transport layers selectively transmit spin‐polarized charge carriers from QDs, enabling CPL‐specific photocurrent generation even in spectral regions without intrinsic …